The present invention relates to passenger comfort or climate control systems employed in the passenger compartment of automotive vehicles and particularly those having large passenger compartments and typically vehicles having body styles of the van or station wagon type.
Heretofore, the heating and air conditioning systems for vans and station wagons have in the majority of commercially produced vehicles, provided for forced air discharge emanating from the dashboard region of the vehicle passenger compartment. Dashboard location of the air discharge outlet in vans and station wagons has resulted in uneven temperature distribution within the passenger compartment causing the system to be set for extreme of temperature control in order to provide adequate heating or cooling for the passengers in the rear section of the passenger compartment. This has often resulted in uncomfortably extreme heating or cooling of the passengers in the forward section of the passenger compartment.
In order to provide increased heating or cooling capacity of the climate control system for the rear passengers, some vehicles have been equipped with auxiliary heat exchangers, in addition to the forward or dash mounted units, with the auxiliary heat exchangers mounted separately in the wall of the vehicle in the rear section of the passenger compartment. Typical installations of this sort have employed a separate heat exchanger in the rear section for circulating engine coolant as a heating medium and an evaporator heat exchanger for circulation of refrigerant for providing cooling to the rear section of passenger compartment. A separate blower has been provided adjacent the rear mounted heat exchangers with a simple blower speed control accessible by the rear passengers. However, passengers seated directly adjacent the blower discharge for the rear heating and cooling heat exchangers have been subject to discomfort when the blower speed was increased to provide greater heating or cooling output responsive to ambient conditions necessitating greater cooling or heating for the comfort of the rear passengers. Manually controlling blower speed to manage rear van temperature requires constant attention from the operator as discharge on temperature varies with vehicle speed, acceleration, ambient temperature and sun load, affecting passenger comfort and satisfaction.
Accordingly, it has long been desired to find a way or means of providing uniform temperature distribution in a vehicle passenger compartment for the comfort of both front and rear passengers; and, it has also been desired to do so in a manner which allowed for individual selection of the temperature in the forward and rear passenger compartment sections. It has further been desired to find a way to provide for automatic temperature regulation despite blower speed changes selected by the passengers.